This invention relates to a pivot mechanism incorporating means to take up wear between two parts thereof.
The invention has particular relevance to car steering columns where historically there has been a problem of how to allow systems such as oar steering columns to pivot, giving positional adjustment, without introducing noticeable backlash or free play into that system, whether that be wear or tolerance induced. FIG. 1 illustrates a simplified arrangement of a car steering column 10 with a steering wheel 1, with the steering wheel movement being illustrated by the arrows A. Reference numeral 2 illustrates a pivot mechanism.
Common systems in use today tend to accept looseness and ignore the results, which leads to a poor user response, or alternatively introduce a multitude of plastics and rubber parts to absorb clearances and damp out movement. These can be difficult to assemble and are prone to mishandling.
As a result of the former problems, FIG. 2 illustrates a housing 3 or the like, with a bolt 4 or the like intended to secure a mounting bracket 5. Such a construction leads to an inherent clearance illustrated by way of example at 6.
FIG. 3 illustrates the tendency to introduce a multitude of plastics and rubber parts and here it will be seen that the mounting bracket 5 is secured between the housing 3 and bolt 4 with the addition of a plastic washer 16 on one side of it and an O-ring 7 and a "top hat" washer 8 on the other side of it.
The foregoing illustrates limitations known to exist in present steering column pivot mechanisms. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.